Spark's Battery Charging Hub is designed to charge up to three Intelligent Flight Batteries in sequence or simultaneously. It optimizes charging based on their power levels and cell voltage. The Charging Hub will limit the charging current to prevent a hazard and prolong battery life when battery temperatures are low.

Charge three Spark batteries at the same time.
Intelligent current-limiting feature prolongs battery life.
 

Spark - Battery Charging Hub × 1
Spark - Charger × 1
Spark - Power Cable × 1

Model: S1CH
Compatible battery charger: Spark Battery Charger (F1C50 Version 2)
Compatible battery model: MB1; 1480 mAh, 11.4 V
Operating temperature range: 32°F to 104°F (0°C to 40°C) 
Input voltage: 13.05 V 
Input current: 3.83 A 
Weight: 0.14 lbs (67.2 g)
Charge time*: Approx. 90 minutes (with three batteries and Spark Battery Charger F1C50 Version 2).
*Charging time was tested in a lab environment at room temperatures of 77°F (25°C). To be taken as reference only.